The Siemens SENTRON 3VA1020-2ED32-0KA0 is a 3-pole molded case circuit breaker (MCCB) rated for line protection, carrying 20 A continuously at 40 °C and interrupting up to 52.5 kA at 240 V AC.
Rated current holds at 20 A from 40 °C up to 55 °C, then derates to 19 A at 60–70 °C — no headroom lost in a warm enclosure unless it runs above 55 °C. Breaking capacity steps down with system voltage: 52.5 kA at 240 V, 32 kA at 415 V, 13.6 kA at 440 V, and 7.5 kA at 500/690 V. The 415 V rating covers most European industrial distribution; the 690 V figure is for high-voltage motor circuits. Maximum power loss is 12 W — negligible for enclosure heat load, but worth noting in a sealed cabinet with dense packing.